Preheat the oven to 350°. Grease a 7x11 baking dish with cooking spray.
Add the berries, lemon juice, coconut sugar, vanilla, and 2 tablespoons of water to a pan and bring to a simmer over medium-high heat. Simmer the berries for 10 minutes, stirring occasionally, then turn the heat off. Add additional coconut sugar to taste, if necessary.
In a separate bowl, whisk together the oat flour, coconut sugar, baking powder, and salt. You can buy oat flour at your local grocery store, or make your own by blending rolled oats in a food processor. I have completed both methods successfully.
Add the melted butter and vanilla to the oats. Mix until the texture is that of cookie dough.
Transfer the blueberry filling to the baking dish. Spoon the oat mixture on top of the berries, and use your fingers to evenly spread it across the dish.
Bake for 40 minutes. Let cool for 45 minutes. This will allow the cobbler to firm up. Serve with your favorite non-dairy and sugar-free ice cream!
Store leftovers in the fridge for 3 days.